14752-72-8Relevant articles and documents
Towards the rational design of ylide-substituted phosphines for gold(i)-catalysis: From inactive to ppm-level catalysis
Handelmann, Jens,Babu, Chatla Naga,Steinert, Henning,Schwarz, Christopher,Scherpf, Thorsten,Kroll, Alexander,Gessner, Viktoria H.
, p. 4329 - 4337 (2021/04/12)
The implementation of gold catalysis into large-scale processes suffers from the fact that most reactions still require high catalyst loadings to achieve efficient catalysis thus making upscaling impractical. Here, we report systematic studies on the impa
Cu/Ni-doped sulfated zirconium oxide immobilized on CdFe2O4 NPs: a cheap, sustainable and magnetically recyclable inorgano-catalyst for the efficient preparation of α-aminonitriles in aqueous media
Nasseri, Mohammad Ali,Ramezani-Moghadam, Simin,Kazemnejadi, Milad,Allahresani, Ali
, p. 4233 - 4256 (2020/07/08)
Abstract: A new multifunctional bimetallic nanocatalyst was prepared by immobilization of Cu/Ni-doped sulfated zirconium oxide on magnetic cadmium ferrite (CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni) and used as an efficient recyclable catalyst for one-pot as well as stepwise preparation of α-aminonitriles under mild conditions. The magnetic nanocatalyst was characterized by FTIR, TGA, VSM, XRD, EDX, FE-SEM, and TEM analyses. Also, the surface acidity of the catalyst was measured by pyridine adsorption assay. The catalyst possesses various active sites which could catalyst a variety of aromatic and aliphatic aldehydes to the corresponding α-amionitriles under moderate to high yields in the presence of aniline. Furthermore, transformation of ketones to the desired α-amionitriles and some bis-aminonitriles was also performed by this method. The catalyst could be readily recovered from the reaction mixture and reused for several times without significant loss of activity. Graphic abstract: A general and efficient method has been developed for transformation of a variety of aliphatic, aromatic aldehydes and ketones to the corresponding α-aminonitriles using a multifunctional recyclable CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni nanocatalyst.[Figure not available: see fulltext.]
Multicomponent Pyrazole Synthesis from Alkynes, Nitriles, and Titanium Imido Complexes via Oxidatively Induced N-N Bond Coupling
Pearce, Adam J.,Harkins, Robin P.,Reiner, Benjamin R.,Wotal, Alexander C.,Dunscomb, Rachel J.,Tonks, Ian A.
supporting information, p. 4390 - 4399 (2020/03/04)
Pyrazoles are an important class of heterocycles found in a wide range of bioactive compounds and pharmaceuticals. Pyrazole synthesis often requires hydrazine or related reagents where an intact N-N bond is conservatively installed into a pyrazole precursor fragment. Herein, we report the multicomponent oxidative coupling of alkynes, nitriles, and Ti imido complexes for the synthesis of multisubstituted pyrazoles. This modular method avoids potentially hazardous reagents like hydrazine, instead forming the N-N bond in the final step via oxidation-induced coupling on Ti. The mechanism of this transformation has been studied in-depth through stoichiometric reactions of the key diazatitanacyclohexadiene intermediate, which can be accessed via multicomponent coupling of Ti imidos with nitriles and alkynes, ring opening of 2-imino-2H-azirines, or direct metalation of 4-azadiene-1-amine derivatives. The critical transformation in this reaction is the 2-electron oxidation-induced N-N coupling on Ti. This is a rare example of formal N-N coupling on a metal center, which likely occurs through an electrocyclic mechanism analogous to a Nazarov cyclization. Conveniently, these 2-electron-oxidized diazatitanacyclohexadiene intermediates can be accessed via disproportionation of the 1-electron-oxidized species, which allows utilization of weak oxidants such as TEMPO
